Impairment of short-term memory associated with low iron stores in a volunteer multidose plateletpheresis donor.

A platelet donor may lose 80-100 mL of blood both in the harness and by blood sampling at each donation, the equivalent of four to five whole blood donations per annum for a donor attending at 2-weekly intervals. A 54-year-old male multidose platelet donor had donated platelets at regular 2-weekly intervals for 6 years. He developed an impairment of anterograde memory (new learning). A self-rating scale revealed a moderate degree of depression [Beck Depression Inventory (BDI) score 22]. Memory testing (Doors and People Memory Battery) showed low scores, particularly for verbal recall and verbal recognition memory. He was found to have a normal haemoglobin of 157 g L(-1) with normal red blood cell indices, but a low serum ferritin (15 ng mL(-1)) and a low serum iron (8.1 mmol L(-1)). Following iron therapy and a return of his iron stores to normal levels, there was an improved BDI score of 13 (minimal level of depression) and a marked improvement in memory test scores. This has been maintained even though he has resumed platelet donation but at reduced intervals.

Performance on two fixed-interval schedules in the absence of neocortex in rats.

Rats with complete surgical removal of the neocortex (neodecorticates) were trained, with milk as the reinforcer, on a 40-s fixed-interval (FI-40) schedule, then on an FI-120, and finally reexposed to the FI-40. Like controls, neodecorticates developed and appropriately adjusted their postreinforcement pauses and response distributions and showed scallop-type responding on the FI-120 and a positive correlation between running rate and the preceding postreinforcement pause on both FI-40 schedules but not on the FI-120. On some variables neodecorticates reached asymptotic levels of performance more slowly than controls. Extended training on the first FI-40 did not differentially affect neodecorticates' performance. The results suggest that neodecorticates retain a functional timing mechanism.